A MIG welder is a wire-fed arc welder that draws a consumable, metal welding wire from a spool inside the welder into the welding gun and, in simple terms, uses high voltage electricity to melt the wire to form the weld. The MIG welding machine also supplies and delivers a metal inert gas (MIG) that flows through the gun concurrent with the feeding of the wire to shield the weld from contamination as the weld is made. MIG welders are also known as GMAW welders or MAG welders (metal active gas welders or gas metal arc welding). Our selection of MIG welders varies by whether they are a flux or inert gas process machine, input and output amperage, wire size, duty cycle and other considerations. For more on welding or welding supplies, see our arc welder accessories, as well as our TIG welders and TIG welding accessories.